Hi..
Edit the /etc/X11/xdm/xdm-config file and comment the following line
! DisplayManager.requestPort: 0
Note: Comment is ! not #
edit /etc/X11/xdm/Xaccess file and add a * to connect all the hosts
Restart ur X server . or just run xdm
Now from ur remote client u can try now
Siddiqu.T